The problem of medication errors has been well documented. In U.S. Pat. No. 6,847,899 to Allgeyer, incorporated herein by reference in its entirety, Allgeyer discusses these issues. In 2012, a Becton-Dickinson study addressed quantification of the problem: Preventable Adverse Drug Events (ADEs) associated with injectable medications impact more than 1 million hospitalizations each year, and they increase annual costs to U.S. healthcare payers by $2.7 billion to $5.1 billion. Those costs represent an average of $600,000 per hospital each year. The medical professional liability cost for inpatient ADEs from injectable medication reaches an industry-wide $300 million to $610 million annually, or as much as $72,000 per hospital. Preventable ADEs are associated with a large range of harmful pharmaceuticals, from heparin to morphine. For example, a common error resulting in fatalities and severe injuries is the so-called 10× error, in which the mistake of a single decimal place occurs in compounding or in programming an infusion pump. In 2007, the well-publicized injection of 1,000 times the intended heparin dose to the newborn twins of celebrity Dennis Quaid highlighted the continuing and long-felt need to control ADEs in clinical settings.
Given the magnitude and seriousness of the ADE problem, there are many ongoing strategies to address and mitigate the risks. Becton-Dickinson utilizes a vibrational spectroscopic technique, wherein the sensor is in contact with the fluid to be analyzed. See US 2012/0226446; US 2012/0226447; and, US 2012/0226448. Approaches utilizing fluorescence, NIR, Raman analysis, and other methods have been developed. These ostensible improvements have turned out to be unsatisfactory, because they are ineffective when used in ambient light, thus requiring some sort of shielding. See, e.g., US 2004/0027568 to Maiefski et al, and US 2009/0157229 to Rulkens et al, both cited during prosecution of the parent application. To date, excluding ambient light has added complexity and costs to workflow and hardware requirements. As yet, however, no system of medication verification has adequately combined the features of reliability, accuracy, low cost, simplicity, and ease of use, especially in a clinical context where ambient light is unavoidable.